Democratic nominee Hillary Clinton’s plan to install half a billion solar panels by the end of her prospective first term will increase electricity prices for American families, according to a study by the free market Institute for Energy Research (IER).

Researchers found Clinton’s plan would increase power price through expanding a solar subsidy, called net metering, which forces utilities to buy the electricity produced by rooftop solar panels often at two to six times the market price. Net metering also forces people who don’t own rooftop solar panels to pay more to maintain the grid.

IER’s findings closely mirror those of a 2015 study by the Massachusetts Institute of Technology (MIT) that found rooftop solar subsides increase costs and the business model isn’t viable without government support.

“Hillary Clinton has gone all in on solar, so it’s important that we examine what sort of impact that will have on energy costs,” Chris Warren, a spokesperson for IER, told The Daily Caller News Foundation. “Solar power is expensive and its inherent unreliability issues impose additional costs on the grid, which leads to higher electricity bills. In fact, the costs imposed by solar increase when more is added.”

Clinton would greatly expand solar power’s federal investment tax credit and net metering to build “half a billion” solar panels by 2020. Clinton’s plan calls for the entire nation to run “entirely on clean energy by midcentury,” with a goal of “getting 50 percent of our electricity from clean energy sources within a decade.” Last year, wind and solar power only accounted for 4.7 and 0.6 percent of all electricity generated in America respectively, according to data from the federal Energy Information Administration (EIA).